The synthesis of thiamine has been described by a number of investigators such as Todd and Bergell in Journ. Chem. Soc., pg. 364 (1937). In these syntheses a pyrimidine ring compound, i.e., 2-methyl-2-amino-5-bromomethylpyrimidine dihydro-bromide and a thiazole ring compound, i.e., 4-methyl-5-.beta.-hydroxyethyl thiazide are condensed to form the thiamine ring structure. This pyrimidine compound is prepared from 2-methyl-4-amino-5-cyanopyrimidine which is formed by the condensation of aminomethylene malononitrile with acetimino ethyl ether, as described in Chapter 16 of the Vitamins, Chemistry, Physiology, Pathology, Vol. III, Sebrell and Harris, Academic Press. Inc., New York (1954).
This procedure therefore depends on the use of the aminomethylene malononitrile which has been a difficult material to synthesize economically. In view of this fact, it has long been desired to provide an economical means of synthesizing aminomethylene malononitrile utilizing inexpensive and readily available starting materials.